<h1 style='color:red'>Hello,wangxiaochun</h1>
<button id='b1'>点点我!</button>
<br>
<img id='i1' src="http://www.wangxiaochun.com/testdir/images/OK.png" >
<script>
document.getElementById('b1').onclick=function(){
    document.getElementById('i1').src='http://www.wangxiaochun.com/testdir/images/wangxiaochun.jpg'
}
</script>

